Nottingham Forest are waiting to discover the full extent of the problem which forced Michael Dawson off against Ipswich.
The Reds skipper hobbled from the field with 11 minutes remaining against the Tractor Boys.
With Tobias Figueiredo currently serving a ban for the red card he picked up in the 5-5 draw with Aston Villa, the last thing Aitor Karanka needs right now is another defensive headache.
A trip to the West Midlands aside, Forest have looked impressively assured at the back over recent weeks.
Cause for concern
Another clean sheet was collected in a 2-0 downing of Ipswich at the City Ground, taking a tally of shut-outs to five in seven Championship outings.
The sight of Dawson making his way from the field on Saturday has, however, offered cause for concern.
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Karanka said afterwards, as reported by the club’s official website: “Michael has picked up a hamstring injury but we will have to see how that settles over the next few days.
“It will be a problem if the injury keeps him out for more than a week but we will have to wait and see.”

With Figueiredo suspended against Ipswich, Michael Hefele stepped into the centre-half void.
He looks a good bet to nail down a starting berth over the coming weeks as Forest face something of a selection poser.
Dawson’s hamstring problem could range from a minor tweak to an untimely tear, with it unclear at this stage how long he will be on the treatment table for.
Enforced rest
If he is in need of an enforced rest, then cover will be required.
Hefele is at the front of the queue and could see Danny Fox come back in alongside him.
The versatile 32-year-old is edging his way closer to fitness and, despite failing to make the matchday squad again versus Ipswich, may be ready after another seven days of training.
The picture remains blurred at present, though, with collective fingers being crossed for a positive update on Dawson once the Reds’ medical team have run a rule over him.